1. Field of the Invention
The present disclosure relates to an electrode assembly, a battery and a device including the same, and more particularly, to an electrode assembly including a combination of three or more types of electrode units having different areas, electrodes having different polarities being formed to face each other at an interface between the electrode units having different areas, and a battery and a device including the same.
2. Description of the Related Art
With technical advancements and increasing demand for mobile devices, demand for rechargeable batteries has sharply increased. Among rechargeable batteries, lithium secondary batteries with high degrees of energy density and high operating voltages, as well as superior life cycles are widely used as energy sources for various electronic appliances as well as a variety of mobile devices.
Generally, a lithium secondary battery is formed to have a structure in which an electrode assembly and an electrolyte are sealed within a battery case, and may be classified as a cylindrical-type battery, a prismatic-type battery, a pouch-type battery, or the like according to the appearance thereof, or may be classified as a lithium ion battery, a lithium ion polymer battery, a lithium polymer battery, or the like, according to the type of electrolyte used therein. Due to the recent trend for the miniaturization of mobile devices, the demand for thin prismatic batteries and pouch-type batteries has increased, and particularly, interest in lightweight pouch-type batteries having easily alterable shapes is high.
The electrode assembly received in the battery case may be classified as a jelly-roll (wound)-type, a stacked (laminated)-type, and a stacked and folded (composite)-type according to the shape thereof. The jelly-roll-type electrode assembly is commonly manufactured by coating metal foil used as a current collector with an active electrode material, pressing the coated metal foil, cutting the pressed metal foil into a band having a desired length and width, separating a negative electrode sheet and a positive electrode sheet using a separator film, and winding the negative and positive electrode sheets and the separator film in a spiral form. The stacked-type electrode assembly is an electrode assembly, manufactured in a manner in which a negative electrode, a separator, and a positive electrode are vertically stacked. Meanwhile, the stacked and folded-type electrode assembly is an electrode assembly, manufactured by winding or folding a single electrode or stacked electrode bodies respectively formed of a negative electrode, a separator, and a positive electrode using a long sheet-type separator.
However, since electrode assemblies according to the related art known up to date may be generally manufactured by stacking unit cells or individual electrodes having the same size, a degree of freedom in the shape thereof may be deteriorated, resulting in limitations in the design thereof. Meanwhile, in order to modify the design, in the majority of cases, complex and difficult processes may be required at the time of manufacturing, stacking or electrically connecting the individual electrodes. In the case of modifying the design, battery capacity per volume may be degraded.
Therefore, the development of an electrode assembly capable of being variously designed while having stability and high capacity characteristics and a battery using the electrode assembly has been demanded.
An exemplary embodiment of the present disclosure may provide an electrode assembly capable of being variously designed as compared to the related art and allowing for a significant decrease in non-utilized space due to design factors to increase space occupancy by using a combination of three or more types of electrode units having different areas, as well as having superior stability by including an electrode unit having the maximum area in the interior of the combination of the electrode units, a battery and a device including the same.